What a masterchain block is in TON
A masterchain block is a block of TON’s coordinating chain, workchain -1. TON runs one masterchain and a basechain (workchain 0) that is split into shards. Shard blocks handle ordinary accounts; each masterchain block records which shard blocks are final, along with network configuration and validator data.
The seqno is the block’s sequence number, increasing by one per block. On the Tongram dashboard the Masterchain block tile shows the latest seqno reported by Toncenter, and the Latest masterchain blocks feed lists recent workchain -1 blocks with their transaction count, shard and time.
Both refresh every 15 seconds while the page is open. A rising seqno means the indexer is seeing new blocks.
What this covers
- This guide explains what the masterchain figures on the Tongram dashboard mean and where they come from.
- It covers TON mainnet as shown by the dashboard. It does not cover validator operation or how shards split and merge.
- Searching for a block by seqno is not a feature of Tongram; the search bar takes addresses, .ton names and transaction hashes.
Steps in Tongram
- Open the Tongram home page. The dashboard is shown when no search result is open.
- Find the Masterchain block tile among the market tiles. The number is the latest masterchain seqno; while data is loading the tile says so instead of showing a value.
- Look at the Latest masterchain blocks panel. Each row shows the seqno, how many transactions the block holds, the workchain and a shard prefix, and the block time.
- Wait 15 seconds. The tile and the feed refresh on their own while the tab is open.
- To connect a transaction to a block, open the transaction: its Block line reads workchain:shard:seqno, which is the block reference the indexer stored.
What you see and where it comes from
- The Masterchain block tile is the last seqno from the Toncenter v3 /masterchainInfo endpoint.
- The Latest masterchain blocks feed is the Toncenter v3 /blocks endpoint filtered to workchain -1, newest first. Transaction count and block time are indexer fields.
- The Latest transactions feed next to it is deliberately basechain (workchain 0) only. Masterchain transactions are mostly validator and configuration bookkeeping, so the feed would say little about ordinary activity.
- The description of masterchain and shards above is protocol fact from the TON documentation; the numbers on the page are provider data.
Freshness and limits
- The seqno on the tile is what Toncenter had indexed at the moment of the request. Another explorer polled at a different second can show a different number.
- Block time comes from the block itself (gen_utime), while the tile timestamp is the moment of the request. Small differences are expected.
- Tongram shows a fixed number of recent blocks; there is no block browser or block search.
- If Toncenter is unavailable, the tile and feed report that and retry; other panels keep working.
Common mistakes
- Reading the masterchain block count as a count of transfers. Ordinary transfers live in shard blocks; the masterchain commits them by reference.
- Expecting a transaction’s Block line to match a masterchain seqno. A wallet transaction usually references a shard block in workchain 0.
- Treating a stalled seqno as a network outage. It can also be the indexer lagging; compare with another source before concluding.